Climate change researchers decry ‘scientific injustice’ in Colombia and Venezuela
When analyzing the role of global warming in rainfall, the World Weather Attribution organization found ‘inconclusive results’ due to a lack of information and models based on the tropics. ‘More science will save lives,’ it urged
A “scientific injustice.” That’s how a group of researchers described the lack of data to establish the role of climate change in the intense rains that fell in Colombia and Venezuela in late June, causing a landslide that killed 27 people in Granizal, Medellín, and which displaced more than 4,700 people in the states of Mérida, Trujillo, and Táchira in Venezuela. World Weather Attribution (WWA), the organization the scientists are part of, seeks to answer the question of the role of climate change in the aftermath of an extreme event. However, in the case of the torrential downpours seen in northern South America, they say, “the results are inconclusive.”
The reasons, explained Friederike Otto, a professor at Imperial College London and founder of WWA, are multiple. First, rainfall in the region is driven by several factors, making attribution more complicated. But there is also a lack of “long-term observational data,” and the global climate models currently in use “don’t do well in the tropics.” They were designed by and for what is known as the Global North.
To conduct the analysis, the team focused on two events. In Colombia, they collected rainfall data from the Magdalena River basin, and in Venezuela, from the Falcón and Maracaibo rivers, from April and June. This gave them a snapshot of what’s happening in the Andean region. For the Venezuelan floods, however, they focused only on the five days with the most rainfall recorded this year in the states of Barinas, Táchira, Trujillo, Mérida, Portuguesa, and Apure, in the plains.
While in Venezuela the rainfall was associated with the passage of a tropical wave, in Colombia, around Medellín, it was a pattern that had been building. Since February, explained Paola Arias, a professor at the University of Antioquia, there has been heavy rainfall, despite the fact that it is typically a dry month. Both April and June also recorded rainfall that was more than double the average for those months in previous years. And the already waterlogged soils were compounded by complex topography, which was affected by changes in land use.
“Historical data show that none of the events were particularly rare,” the WWA report says. In the current climate, which is already 1.3°C warmer than pre-industrial times, three months of rain like those seen in Colombia can occur every 10 years, while such intense five-day downpours in Venezuela are expected to occur every three years. But they couldn’t determine exactly what role climate change played in this equation, or whether the region’s rainfall will tend to increase or decrease in the face of a warmer climate.
According to Mariam Zachariah, a research associate at Imperial College London, the fact that they haven’t concluded what role climate change played “doesn’t mean it doesn’t play a role; it’s more about trust in the models.” “Unfortunately, extreme weather is not well-understood in northern South America,” Arias added. “In this case, it’s not clear whether climate change increased rainfall, but it’s almost certainly increasing the risk of heat waves, droughts, and fires in Colombia and Venezuela.”
In other words, the lack of data means both countries must be prepared for anything. Regarding the landslide in Colombia, the experts also warned that internal displacement has forced people to settle in informal settlements, right on the hillsides, and that deforestation and the conversion of moorlands to agriculture “has reduced the capacity of natural ecosystems to regulate flooding caused by rainfall and has increased susceptibility to landslides.”
“More investment in climate science is urgently needed to understand the changing risks and prepare for what’s coming. More science will save lives,” Arias concluded. Her statement echoes the words of the Inter-American Court of Human Rights (IACHR) a few weeks ago, when it published its advisory opinion on the obligations of states in the face of the climate emergency: there is a right to science. “This right includes the prerogative to participate in scientific progress and enjoy its benefits, without discrimination.”
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